Generic throttling metrics namespace and BigtableIO write throttling counter

[Abacn]

Fix #19632

Introduce a namepace named "beam-throttling-metrics", put under java core's Metrics.java, and use this namespace for Dataflow worker

Currently, Dataflow worker only considers several "known" namespace for throttling metrics, including bigquery streaming inserts, etc. After this change, "beam-throttling-metrics" is added to known namespace for batch Dataflow worker; and streaming dataflow worker will react on all counters named "throttliing-msecs"

• Introduce a generic throttling namespace and counter

• Dataflow accumulates throttling time from generic throttling counter

• Apply throttling counter to BigtableIO write

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[Abacn]

before - agressively scale up until get completely stuck, then no longer scale up because average CPU usage below 5%, until get cancelled

after - multiple scale down event

though there are some caveat

• once throttling signal relieved, autoscaler tends to scale up again, causing bouncing between throttling-relieved

• the last batch seems stuck to flush indefinitely. This is a known issue for BigtableIO: fix: have a timeout on the wait when closing BigtableIO#Writer #29548 introduced attemptedTimeout config to force the future expire in finite time to mitigate the issue, but the underlying issue always present

[github-actions]

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[Abacn]

Java PreCommit failed twice different tests failing, not related to this PR

run#1

testIsAvailableAlwaysWakenUp (org.apache.beam.runners.flink.translation.wrappers.streaming.io.source.unbounded.FlinkUnboundedSourceReaderTest) failed

testLatencyAttributionToCommittingState[0: [streamingEngine=false]] (org.apache.beam.runners.dataflow.worker.StreamingDataflowWorkerTest) failed

run#2

testMultipleClientsFailingIsHandledGracefullyByServer (org.apache.beam.runners.fnexecution.logging.GrpcLoggingServiceTest) failed

[Abacn]

R: @igorbernstein2 @ahmedabu98

[github-actions]

Stopping reviewer notifications for this pull request: review requested by someone other than the bot, ceding control. If you'd like to restart, comment assign set of reviewers

[ahmedabu98]

Few questions but overall LGTM